Abstract
A housing part (10) for a sensor has a transparent, hollow base body which has a toothing (14) in the form of a straight-toothed gearwheel in a circular-cylindrical emission region on its lateral surface. A circuit board of the sensor is partially arranged in the housing part (10). The circuit board has at least one light source which faces the emission region.
Claims
1. Housing part for a sensor, said housing part comprising: a transparent, hollow base body having a toothing in the form of a straight-toothed gearwheel in a circular-cylindrical emission region on a lateral surface of the housing part.
2. The housing part according to claim 1, wherein the hollow base body contains at least one light-diffusing filler.
3. The housing part according to claim 1, wherein, the toothing is delimited on the lateral surface by a rough structure.
4. The housing part according to claim 3, wherein the rough structure extends through at least one tooth gap of the toothing.
5. The housing part according to claim 1, further comprising a coupling element having a V-shaped cross-section on an interior wall of the emission region.
6. A sensor said sensor comprising: a circuit board partially arranged in a housing part, the housing part having a transparent, hollow base body having a toothing in the form of a straight-toothed gearwheel in a circular-cylindrical emission region on a lateral surface of the housing part, wherein the circuit board has at least one light source which faces the emission region.
7. The sensor according to claim 6, wherein the light source has two colours.
8. The sensor according to claim 6 wherein the housing part has a coupling element having a V-shaped cross-section on an interior wall of the emission region and the at least one light source faces the coupling element.
9. The sensor according to claim 6, wherein the circuit board is partially arranged in a housing pipe, wherein the housing pipe is connected to the housing part by means of a connecting region of the housing part.
10. The sensor according to claim 9, wherein the circuit board has electrical plug contacts arranged in a plug region of the housing part and extend through openings of a closing element formed as one part with the housing part, wherein the emission region is arranged between the plug region and the connecting region.
11. The sensor according to claim 6, wherein the hollow base body contains at least one light-diffusing filler.
12. The sensor according to claim 6, wherein the toothing is delimited on the lateral surface by a rough structure.
13. The sensor according to claim 12, wherein the rough structure extends through at least one tooth gap of the toothing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Exemplary embodiments of the invention are depicted in the drawings and are explained in more detail in the following description.
[0018] FIG. 1a shows a side view of a housing part according to an exemplary embodiment of the invention.
[0019] FIG. 1b shows an isometric view of the housing part according to FIG. 1a.
[0020] FIG. 2 shows a cross-sectional depiction of the housing part along the line II-II in FIG. 1a.
[0021] FIGS. 3a-c show isometric depictions of a housing part according to an exemplary embodiment of the invention.
[0022] FIG. 4 shows a housing part according to an exemplary embodiment of the invention, into which a circuit board has been inserted, in a transparent isometric depiction.
[0023] FIG. 5 shows a front view of the housing part according to FIG. 4.
[0024] FIG. 6 shows a schematic sectional depiction of a sensor according to an exemplary embodiment of the invention.
EXEMPLARY EMBODIMENTS OF THE INVENTION
[0025] In FIGS. 1a and 1b, a housing part 10 according to an exemplary embodiment of the invention is depicted. The latter consists for example of a polycarbonate, which contains a light-diffusing filler (ALCOM? PC LD of Albis Plastic GmbH, Germany). The housing part 10 has a connecting region 11, an emission region 12 and a plug region 13 one after the other along its longitudinal axis L. Each of these regions 11, 12, 13 respectively has a circular-cylindrical cross-section. The housing part 10 is hollow, and open on both of its ends. In the emission region 12, a toothing 14 in the form of a straight-toothed gearwheel with a tooth gap runs around the housing part 10. A length of the toothing along the longitudinal axis L is for example 4.5 mm. The toothing 14 is manufactured as one part with the housing part 10 from the polycarbonate in an injection moulding method. The surfaces of the toothing are polished. The emission region 12 further has a textured structure 15, in which the surface of the housing part 10 has been roughened after manufacture in the injection moulding method by means of a subsequent texturing method to a surface roughness e.g., of Ra=1.20 ?m (corresponding to VDI 3400 REF 21). The textured structure 15 is sub-divided into a first region 151, which runs around the housing part 10 in an annular manner between the toothing 14 and the connecting region 11, a second region 152, which runs around the housing part 10 in an annular manner between the toothing 14 and the plug region 13, and a third region 153, which runs through the tooth gap of the toothing 14 and connects the first region 151 and the second region 152 of the textured region 15 to each other. In the plug region 13, the housing part 10 has an outer thread 131.
[0026] FIG. 2 shows a cross-sectional depiction of the emission region 12 in the region of the toothing 14. It can be seen that the teeth of the toothing 14 respectively have a tooth height h for example of 0.25 mm and that a tooth angle ? is for example 120 degrees. The cavity 16, which extends through the housing part 10, is widened at two opposite positions by recesses 161, 162 in the base body of the housing part 10. These recesses 161, 162 respective extend over the entire length of the housing part 10. They are provided to make it possible to insert a circuit board into the cavity 16, and to precisely position the circuit board in the latter. A V-shaped coupling element 17 is formed as one part with the base body of the housing part 10 underneath the third region 153 of the textured structure 13 on the interior side of the base body of the housing part. It is provided to couple light which is emitted by a light source arranged on the circuit board into the emission region 12 of the housing part 10. Opposite the coupling element 17, a stiffening bar 163 formed as one part with the base body is arranged on the inside of the base body. Said stiffening bar runs along the longitudinal axis L of the housing part 10.
[0027] FIGS. 3a and 3b show a view into the cavity 16 of the housing part 10 through the opening of its connecting region 11. This opening is provided to insert a circuit board into the cavity 16. It can be seen that a recess 164 is provided in the edge of the connecting region 11, opposite the stiffening bar 163. FIG. 3c shows a view into the housing part 10 through the opening of its plug region 13. A disc-shaped closing element 18 is arranged in the cavity 16 and formed as one part with the latter. It has several openings 181, which are provided for receiving receive plug contacts.
[0028] FIG. 4 shows how the circuit board 20 has been inserted through the connecting region 11 into the cavity 16, wherein it is guided into the two recesses 161, 162 until it abuts on the closing element 18. It protrudes a little further out of the housing part 10. After the circuit board 20 is completely inserted into the housing part 10, a light source 21 in the form of an LED that has two colours, which is arranged on the circuit board 20, comes to rest under the coupling element 17, as depicted in FIG. 5. Light beams 31, 32, which are emitted by the light source 21, are first coupled by the coupling element 17 into the base body of the housing part 10 and then into the toothing 10 and reflected on the latter. In FIG. 5, only a single reflection path is represented for each of the two light beams 31, 32, which leads to light being emitted in the direction pointing downwards in FIG. 5. In practice, however, many different reflections take place, such that light is emitted radially in all directions around the housing part 10. The colours of the light source 21 are for example green and red. If the light source 21 simultaneously emits light in both colours, this light is mixed by the toothing 14 depending on the mixing ratio to form orange or yellow light.
[0029] FIG. 6 shows how the housing part 10 and the circuit board 20 are combined with further components to form a complete sensor 40 according to an exemplary embodiment of the invention. The connecting region 11 of the housing part 10 has been connected to a housing pipe 41. The circuit board 20 extends out of the connecting region 11 into the housing pipe 41 and is connected on its end (not depicted) facing away from the housing part 10 to an inductive sensor element 42. In order to contact the sensor element, several plug contacts 43 in the plug region 13 of the housing part 10 are guided through the openings 181 of the closing element 18 and connected to the circuit board 20. In this manner, it is possible to electrically contact the sensor 40 in its plug region 13 by means of a plug connection. The contact can be secured by screwing a plug connector to the housing part 10 by means of the outer thread 131.
